Normal blood vessel function is essential for survival. The vascular system must integrate
diverse physical and chemical signals and respond immediately by regulating blood flow to
different organs in response to their individual needs and the collective good of the
organism. It must also adapt to chronic changes in organ requirements by remodeling to
alter blood vessel caliber (eg, arteriogenesis) or the density of the vascular network (eg,
angiogenesis). Powerful positive and negative forces are activated under both conditions; in …